Vibration assisted machining (VAM) is an advanced manufacturing technique that is utilized in various applications such as manufacturing master molds for gratings and diffractive optics and die masters for stamping. VAM techniques may provide advantages, including: decreased tool wear; expanded material machining capability; and increased nano-scale feature capabilities, as compared to single point turning machining.
VAM further enables machining of materials, such as, for example, silicon carbide, that are extremely difficult to machine using single point diamond turning techniques due to excessive heating of the diamond tip. VAM systems vary in complexity and utility. VAM systems, such as the Ultramill system developed at North Carolina State University, use two piezoelectric (PZT) actuators mounted sided by side to drive a diamond tool in an elliptic trajectory. The minor and major axes of the ellipse trajectory are determined by a T-shaped linkage used to couple the PZT actuators to the cutting tool and the amplitude and phase of the drive signals used to drive the PZT actuators. However, this linkage geometry and driving method does not allow for reduced tool lead-in and lead-out zones (i.e., transition zones) when entering or exiting a workpiece when operated in a steady-state condition.